Question

Don’t understand b) pls explain

Answer 1

−s2+2st−t2−s+t

Explanation:

−(s−t)−(s−t)2

distributed would be

−s+t+−s2+2st+−t2

Answer 2

Below in bold.

Explanation:

-(s - t) - (s - t)^2 Take out (s - t):

= (s - t)( -1 - (s - t)

= (s - t)(t - s - 1). <---- Factored form.

Or, if you want to expand the expression:

-(s - t) - (s - t)^2

= - s + t - (s^2 - 2st + t^2)

= -s^2 + 2st - t^2 - s + t.